Examination,treatment, or the like of liquid films.



. v 0. v. BOYS. EXAMINATION, TREATMENT, OR THE LIKE OF LIQUID FILMS.

' APPLICATION FILED OUT. 23, 1911.

Patented Dec.31,1912.

2 SHBETSSHEET 1.

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0. V. BOYS.

EXAMINATION, TREATMENT, OR THE LIKE 0F LIQUID FILMS.

APPLICATION FILED OCT. 23, 1911.

Patented Dec. 31, 1912.

2 W H r n E f H l s u h. w n z E n A E 7 m 1. L m 1F a m w COLUMBIAPLANOGRAPH c0., WASHINGTON, D. c,

UNITED STATES PATENT OFFICE.

CHARLES VERNON BOYS, OF LONDON, ENGLAND.

EXAMINATION, TREATMENT, OR THE LIKE OF LIQUID FILMS.

T all whom it may concern Be it known that 1, CHARLES VERNON Boys, F. R.S., a subject of the King of Great Britain and Ireland, and residing at66 Victoria street, London, S. England, have invented certain new anduseful Improvements in or Relating to the Examination, Treatment, or theLike of Llquid Films, of which the following is a specification.

This invention relates to methods of and means for demonstrating certainproperties of liquid films, such as soap bubbles, which have theproperty of becoming sufficiently thin without breaking; in particular,according to this invention, such films may be treated for thedevelopment of their colors with a certainty, brilliancy, variety andregularity that has not hitherto been possible, and so cheaply that thenecessary apparatus may serve either as an attractive toy or asphilosophical apparatus for use in the laboratory.

WVit-h these objects the invention consists of a method ofexhibitingphenomena of the type indicated which consists in supportingperipherally a liquid film and rotating said film partly by rotating airin contact with at least one side thereof and partly by the applicationof forces to its points of peripheral support.

The invention also consists in the combination of a hollow vesselcontaining air, said vessel having an annular film-receiving portion anda support in relation to which said vessel together with its containedfluid is rotatable.

The invention further consists in the methods of and means fordemonstrating the properties of liquid films to be hereinafter describedand particularly pointed out in the claims.

Referring to the accompanying drawings which illustrate difierent formsof the invention; Figure l is a side elevation partly in section of afilm cup or box arranged to rotate in bearings provided in its packingcase, this figure also showing in dotted lines the film, cup, bottles ofsolution and other parts packed for transport; Fig. 2 is an endelevation corresponding to Fig. 1; Fig. 3 is a side elevation of the lidof the packing case; Fig. 4: is an end elevation of the same; Fig. 5 isa vertical section of the upper part of the film box showing a removablering Specification of Letters Patent.

Application filed October 23, 1911.

Patented Dec. 31,1912.

Serial No. 656,271.

right and left hand sides respectively half sections of alternativeforms of glass shade,

while Fig. 8 is a plan view of the removable.

ring showing also an ovoid body surrounded by the film.

In carrying the invention into effect according to one form by way ofexample, the film box, a, which is open at the top and has an inturnedrim, 6, is supported by means of a boss, 0, on an axle, (Z; this axle isarranged to rotate in metal bushes, e, 6, provided in the sides of thebox or case, f, in which the film cup, a, and its accessories are packedfor transport purposes. The weight of the cup, (1, may be taken by asteel ball, it, forced into a recess in the lower bush, 6. The spin ningcup is provided with a removable annular portion or ring, 2', with achamfered inner edge (similar to that shown in Fig. 6 to be hereinafterreferred to) which is the actual carrier of the film, the latter beingindicated by the chain line, is. A transparent cover, m, of conicalshape having rein forced edges, 1%, fits over the top of the spinningcup.

With the packing box standing on its side as shown and the lid removed,the axle, d, is readily accessible and can be turned with sufiicientrapidity by hand to rotate the film cup.

Rotation of the cup and cover carries around the air inclosed by theseparts so that the film itself is rotated partly by the rotating air incontact with its superficial areas and partly by forces due to adhesionand viscosity arising from the film-carrying portion of the cup. Whenuniform conditions have been established the whole appa ratus, which maybe regarded as a vessel divided by a film into two chambers, with theinclosed air, rotates as one body.

The spinning cup, (4, with its inturned rim is preferably madewater-tight so that some soap solution may be placed in it and retainedwhether the box is spinning or not with the axle vertical or inclined.The cup or box, a, mounted on the free upper extremity of the axleserves as a flywheel and maintains the rotation with sutlicientuniformity. A mirror, 0, may also be used in conjunction with the devicedescribed for a purpose to be subsequently indicated. This mirror mayconveniently be held in a sawdraft, a", cut in the block, 8, having acylindrical projection, 25, which fits into an appropriate hole in theside of the case,

The cup, a, wit-h its cover, m, fits into a circular hole ofcorresponding cross-section in a cross partition, u, as shown, fortransport purposes, the end of the axle fitting in a correspondingrecess, '0, formed in the half end, w, of the box. The other half end,00, is formed in one with the lid, 2, this lid being arranged to slidein grooves, 2, in the side of the box. In the angle between the halfend, 00, and the lid, 2, and in the center line of the box, a steppedmember, 3, is provided, each step of which carries a pm, 4.

A corresponding recess, 5, is provided as shown in the case itself, theobject being to support the case, f, in any of a number of inclinedpositions, one of which is shown by the dotted line, f, slipping beingprevented by the particular pin, 4:, concerned entering the recess, 5.Bottles of soap solution, 6 and 7, are shown packed in the box, f,together with the mirror block, 8, and the mirror itself, 0, the latterbeing slipped through a recess, 15, at the back of the partition, to.

As the beauty of the effects is so much greater when the soap filmstretched in the rim is plane, than when it is curved the planeness ofthe film is insured by providing a hole, 8, in the rim near the inneredge. Then when the cover, m, is placed in position and the box is spun,the film whether originally plane or not will become and will remainplane in spite of the changes of pressure which occur in consequence ofcentrifugal force acting on the air above and below the film.

If it is desired to experiment with a convex or concave film, it ismerely necessary to close the hole with a soap film. It is desirablethat the interior of the box should be dark in color.

In order to attach a film to the rim, the latter should first be wettedwith the liquid being used; a bubble blown by means of a pipe, forexample, may then be placed upon the rim and if a single plane film onlyis required the film on one side should be broken. According to anothermethod, some solution may be poured into the box which is spun so as towet the sides up to the rim; a bubble is then blown in contact with theliquid so as gradually to rise in the box and attach itself to the rim.Or again, a piece of rubber, card, celluloid or other suitable -materialmay be wetted with the solution and drawn over the edge of the rim. Ifthe film in any case closes the air vent in the rim, this may be brokenwhen desired with a point of blotting paper. If loose rims are employedthey need only be dipped in a solution and replaced, the vent hole, ifnecessary being cleared of film. The transparent cover may next beapplied and the box spun by the action of the hand on the axle. Rings ofcolor, being interference colors at first of a high order and graduallyof lower orders, are formed which have so great a brilliancy and varietyas to make the apparatus serve as an attractive toy. If the rotation bestopped and the axle inclined a little from the vertical the colorsarrange themselves ultimately in a series of parallel straight bands butpass through many intermediate forms. If the rotation be started againthese bands or patterns are drawn out into spirals of ever changingbrilliancy and color which gradually change into a new ring pattern.

If the solution of soap and water be made without glycerin or with verylittle, the development of the colors as far as the black may be watchedin a very short time and even the who-1e film may become black. A blackportion may be drawn out into a spiral of several turns. By the additionof glycerin to the solution the process of thinning and the developmentof the color rings may be delayed, and the film be made to last longer.By raising and lowering the cover to admit an air draft when the film isthin or by breathing upon the film other color changes may be produced.

According to a modification shown in Fig. 5, an ordinary glass funnel,9, is inverted and placed on the removable ring, In such a case there isa leakage escape of air around the rim of the funnel due to centrifugalforce, together with a central indraft down the stem, 10. If when theapparatus is spinning the stopper from a bot-- tle of ammonia is heldfor a moment near the end of the stem, the action of the ammonia vaporimmediately causes a new color pattern at the center, which beingthicker than the surrounding film, is unstable in that position and verysoon makes a kaleidoscopic change in moving toward the periphery of thefilm. It is not necessary for this purpose to have the complete glassfunnel; a celluloid conical shade as shown in Fig. 1 pierced at theVertex, produces a similar result.

Removable rims or rings with holes of various sizes may be employed, butit is desirable when plane films are required to provide an aperture ora scalloped or corrugated edge or other means by which the air pressureon the two sides of the film may be employed.

According to the modification shown in Fig. 6, the film cup, a, isprovided with an inturned rim, Z), having an aperture, 8, the removablering, 2', being dispensed with.- The inner edge of the rim should bechamfered so that the film stretched upon it may lie accurately in aplane. In this case the amount of liquid which the box will contain whenspinning rapidly is approximately equal to that which lies in theannular space inclosed by the wall and bottom of the box and acylindrical (or more strictly parabolic) surface passing through theexterior edge of the air vent.

The box, a, may be made of any convenient material which preferablyshould not be affected by the water; for instance, pewter,

a over covers of the clock-glass shape is that when used in front of awindow, the light reflected upon the curved glass surface, is not seensuperposed upon the film; the conical covers shown also possess the sameadvantage.

As shown in Fig. 1, a mirror, 0, may be provided so that a ray of light,13, may be reflected from the mirror on to the film and so to the eye ofthe observer, who at the same time can see the film by means of rays,14. The patterns due to the different rays in such a case are entirelydifferent in color and the contrast is the more striking as both sets ofcolor patterns can be seen at the same time.

The apparatus described above may also be used to demonstrate thecentrifugal force of the rotating air. In this case the box, a, is spunwith a film stretched on the rim but without a cover. If the small hole,8, is open the internal pressure at that distance from the axis is equalto the pressure of the atmosphere but the internal pressure nearer theaxis is less and therefore the film is drawn inward to an extentdepending upon the speed of rotation.

If the air hole, 8, is closed and the film is initially plane, theaverage internal pressure acting on the film is equal to that of theatmosphere acting externally but the internal pressure is less nearerthe axis and greater toward the periphery, such distribution of pressurebeing shown by the depression of the center and the elevation of theouter parts of the film.

Other properties of liquid film may be demonstrated with the sameapparatus; thus Fig. 8 shows a removable ring, 2', across which a filmis supposed to be stretched, with an ovoid body, 15*, resting on the rimsupposed in a vertical plane. Such ovoid body may be conveniently madeby blowing a birds egg (preferably one somewhat smaller than the egg ofa house-sparrow) and then sealing the hole. In such a case the egg is ina position of equilibrium rendered stable by the action of the film. Ifthe film box or ring is turned slowly, the egg will roll end over end,but if quickly, it will jump and roll always keeping its maximum sectionhowever in the plane of the film. The ring, if removable, should fit thebox so as not to fall off when in a vertical position. Like bodies ofother form such as prolate or oblate spheroids, disks, etc., ifsufficiently light, may be made to rest or move in a similar manner. Thefilm box, a, may also be spun as a free spinning top, but this is not soeasily under control.

lVhile any liquid film having the property indicated above of becomingsufficiently thin without breaking may be used, for example, soapsolution or melted resin, nevertheless a solution of one part of oleateof soda in forty parts of soft water with glycerin added in anyproportion up to two-thirds by volume according to the desired speed ofthinning, is eminently suitable. If material such as melted resin isused, the apparatus should be suitably warmed, but I'lbIigS with smallerapertures are then prefera e.

The underlying principle of the invention which consists in rotating aliquid film partly by rotating air in contact with it and partly byperipheral forces due to the action of the film support may clearly becarried into effect in a veriety of ways different from those described.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is 1. A method of exhibiting phenomena of thetype indicated, which consists in supporting peripherally a liquid filmand r0- tating said film partly by rotating air in contact with at leastone side thereof and partly by the application of forces to its pointsof peripheral support.

2. A method of exhibiting phenomena of the type indicated, whichconsists in closing an open hollow vessel by a liquid film and rotatingsaid vessel about an axis transverse to said film.

3. A method of exhibiting phenomena of the type indicated, whichconsists in closing an open hollow vessel by a plane liquid film, androtating said vessel about an axis perpendicular to the plane of saidfilm.

1. A method of exhibiting phenomena of the type indicated, consisting inpreparing a liquid film, rotating said film and treating said rotatingfilm to the action of vapors.

5. A method of exhibiting phenomena of the type indicated, consisting inpreparing a liquid film, supporting thereby a light body having amaximum cross-section and rotating said film in a vertical plane.

6. In combination, an open hollow vessel containing elastic fluid, saidvessel having an annular portion to receive a liquid film and a supportin relation to which said ves sel together with its contained fluid isrotatable.

7. In combination, an open hollow vessel having an annular portionclosed by a liquid film, said vessel containing elastic fluid to contactwith one side of said film and means containing elastic fluid in contactwith the other side of said film for inclosing the same.

8. I11 combination, a hollow vessel having an annular portion closed bya liquid film, said vessel containing elastic fluid in contact with oneside of said film, means con taining elastic fluid in contact with theother side of said film for inclosing .the same and means for equalizingthe fluid pressure on the two sides of said film.

9. In combination, a hollow vessel composed of separable contactingparts one of which is transparent and divided by a liquid film intochambers each inclosing elastic fluid together with means for equalizingthe fluid pressure on the two sides of the film.

10. In combination, a hollow vessel having an annular portion to receivea liquid film and a transparent cover, said cover having a peripheralfluid outlet and an axial inlet.

11. In combination, a rotatable annular member, to receive a liquid filmand a mirror so disposed in proximity to said film that it can be viewedsimultaneously by light reflected from said mirror and by light not soreflected.

body, said body being held by the action of the film in a stableposition while rolling or jumping.

14:. In combination, a rotatable film-carrying annular member and alight ovoid body, said body being held by the action of the film in astable position while rolling or jumping.

15. In combination, a hollow vessel composed of separable contactingparts and divisible by a liquid fllm'into chambers each inclosingelastic fluid together with a support in relation to which said vesselis rotatably disposed.

16. In combination, a hollow member and a separable member associatedtherewith to form a chamber divisible by a liquid film into parts eachinclosing elastic fluid, at least one of said members being transparent.

17 In combination, a hollow vessel having an annular portion to receivea liquid film and a detachable transparent cover therefor.

18. In combination, a film-carrying hollow member and a second memberseparable therefrom and covering the same, one of said members beingtransparent.

19. In combination, an open hollow vessel closable by a liquid film anda support in respect to which said vessel is rotatable.

20. A hollow vessel having an annular portion with a uni-planarchamfered edge to receive a liquid film.

21. In combination, an open hollow vessel having an inturned rim portionclosable by a liquid film, and a support in respect to which said vesselis rotatable. I

22. An open hollow vessel having an annular part of a minimumcross-section closable by a liquid film and a support in respect toWhich said vessel is rotatable.

In testimony whereof, I aflix my signature in presence of two witnesses.

CHARLES VERNON BOYS.

WVitnesses:

HENRY H. GRUNING, BERTRAM I-I. MATTHEWS.

Copies 01' this patent may be obtained for five cents each, byaddressing the Commissioner of Patents, Washington, D. G.

